Last, P.R., Naylor, G.J.P. and Manjaji-Matsumoto, B.M. 2016. A revised classification of the family Dayatidae (Chondrichthyes: Myliobatiformes) based on new morphological and molecular insights. Zootaxa 4139(3): 345-368. http://doi.org/10.11646/zootaxa.4139.3.2.

Taxonomic Notes:

Last et al. (2016) described the genus Pateobatis, consisting of five medium-size to very large, marine whiprays previously placed in Himantura (including uarnacoides). Previously on The IUCN Red List, bleekeri was treated as a junior synonym of uarnacoides (M. Manjaji pers. obs. 2007). However Pateobatis bleekeri is considered a valid species by Last et al. (2016).

Justification:
This is an amended version of the 2004 assessment to accommodate the change in genus name from Himatura to Pateobatis.

Bleeker's Whipray (Pateobatis uarnacoides) occurs from India to Java, Indonesia, in shallow waters to at least 30 m depth. It is taken in very large quantities in demersal tangle net, bottom trawl, trammel net and Danish seine fisheries off India, Indonesia and Malaysia, particularly in the fishery that targets rhynchobatid rays. Although no species-specific data are available, overall catches of stingrays are reported to be declining, with fishermen having to travel further and further to sustain catch levels. All catches are generally retained and marketed. Little specific information on catches is available in other parts of the species' range, but population declines elsewhere are inferred from Indonesia. Marine pollution and coastal degradation has also impacted this species' coastal habitat. Given continuing high levels of exploitation throughout much of this species' range and evidence for declines in catches of stingrays off Southeast Asia, this species is assessed as Vulnerable.

This inshore stingray occurs on soft substrates, to depths of at least 30 m (Compagno 1998, White et al. 2006). It is known to range into rivers and estuaries in Sabah (Manjaji 1997), and one specimen was caught in an ox-bow (saltwater) lake, near the mouth of Kinabatangan River (Sabah) (Manjaji 2004). Reproduction is viviparous with histotrophy (White et al. 2006). The species attains at least 119 cm disc width (DW) (300 cm total length), males mature at about 76 cm DW (Compagno 1998, White et al. 2006). Size at birth is less than 24.2 cm DW (White and Dharmadi 2007). Nothing else is currently known of the life-history parameters of the species.

Flesh is utilized fresh or salted and dried for human consumption (locally), vertebrae are dried and exported to the Orient, the denticulate skins are dried and are exported to either Thailand or elsewhere in Indonesia for manufacturing into items such as wallets, belts, handbags, shoes etc, which are becoming increasingly sought after and are beginning to be advertised on web sites in some developed countries (e.g., USA) (White et al. 2006, Authors pers. obs.).

Pateobatis uarnacoides is taken in very large quantities in demersal tangle net, bottom trawl, trammel net and Danish seine fisheries off India, Indonesia and Malaysia, particularly in the fishery that targets rhynchobatid rays (Compagno 1998, White et al. 2006, Authors pers. obs.). It is also captured by bottom longlines in Vietnam (C. Vidthyanon pers. obs. 2007). In Indonesia, although this species is still caught in large numbers, the fishing vessels have to travel large distances from many cities to sustain catch levels (W. White pers. obs. 2007). Thus, it is apparent that many areas, particularly close to major cities, have been heavily fished. The rhynchobatid fisheries are very intensive in this region, thus the level of exploitation is extremely high. In Indonesia, the dried ray meat that is obtained from catches of the rhynchobatid gill net fishery is an extremely important source of protein for the country. This will presumably increase in the future, thus of great concern to batoid species such as P. uarnacoides.

Inshore fishing pressure is high throughout much of this species' known range in the Indian Ocean and Southeast Asia. In Southeast Asia (and presumably in other parts of its range, such as India), most specimens caught as bycatch by commercial fisheries (especially trawlers) are usually retained and marketed for human consumption (B.M. Manjaji, W. White, Famhi and Vidthayanon pers. obs). Artisanal and industrial fishing pressure is intensive off India (Flewwelling and Hosch 2006, Morgan 2006). Fisheries throughout India operate on an open access basis. Inshore marine species are thought to be fully or overexploited, with extensive use of illegal mesh sizes reported, and increasing ever-increasing bottom trawl effort (Flewwelling and Hosch 2006, Morgan 2006). Demersal species, such as this, suffer more fishing mortality than pelagic species on the eastern coast of India and declines in demersal shrimp and fish stocks have led to fishery closures in areas of the western coast (Morgan 2006). India's inshore fisheries are generally characterised by declining catch rates, recruitment and biomass and a shift from regular landing patterns (Flewwelling and Hosch 2006). Although no species-specific data are available on catches, this species may share the limiting life-history characteristics similar to many elasmobranchs, making it vulnerable to depletion.

Marine pollution and coastal degradation has also impacted the coastal habitat of this species (including estuaries) (Morgan 2006). Extensive trawl and gillnet fisheries also operate off Pakistan (Khan 2006) and in other areas of this species' range in the Indian Ocean.